About step by step

Hello! In a query like SELECT parent, children FROM Parent parent LEFT JOIN p.children children GROUP BY parent maybe it would be good if it will return a list of Object[2], where the second object is a list of children of a parent. Because creating a query to get a list of parents, then fetching

Databases are also supported by ObjectDB. The combination of Object Database features ... . Up to 9,223,372,036,854,775,808 entity objects per database file. Unlimited database connections (limited only by operating system resources). Unlimited CPUs and cores. Reliability and Stability Recovery from failure by

previously. I have copied database file to slave... and so on by manual. It worked fine. But if I restart ... UP TO DATE] 6) got this on slave after step 3:
com.objectdb.o.UserException: Optimistic lock failed ... .java:203)
at java.lang.Thread.run(Unknown Source) 7) got exception from step 6 every time

downloading and running the tutorial, if following stepbystep doesn't work. pryashrma ... I followed each and every step of NetBeans/JPA Web Application Tutorial but when i am trying to run the web application the following error is prompted on the run console: Start is in progress